INDIANAPOLIS (AP) — A man already charged in a deadly
house explosion in Indianapolis tried to arrange for a key witness to be
killed, despite signs in the jail warning inmates that their phone calls
were recorded, prosecutors said Thursday.

Mark Leonard
also wrote and signed a contract to hire a hit man and confirmed in a
phone call with an undercover federal agent posing as a hit man that he
wanted the witness dead, Marion County Prosecutor Terry Curry said at a
news conference in downtown Indianapolis.

Leonard, his
girlfriend, Monserrate Shirley, and his brother Bob Leonard already face
life in prison without parole if convicted of felony charges including
murder and arson in the Nov. 10 blast. Teacher Jennifer Longworth and
her husband, John, were killed in the explosion that also left 33 homes
in the Richmond Hill subdivision so damaged that they had to be
demolished.

Curry said
Leonard has now also been charged with one count of conspiracy to commit
murder.

Leonard
asked a fellow inmate at Marion County Jail if he could put him in touch
with a hit man to kill the witness who he said was "blabbing," according
to the affidavit. The inmate, who Leonard believed belonged to a
motorcycle gang, indicated he could help, and they drew up a contract
agreeing that Leonard would pay a $15,000 kill fee on his release.
Leonard even drew a map indicating the location of the witness' home,
the affidavit says.

Leonard also
offered a $5,000 bonus on two conditions: that the hit man would first
persuade the witness to call 911 and recant his statement to
investigators, and that the death would look like a suicide.

The
affidavit does not describe how or when federal authorities became
involved, and Curry declined to provide details, but soon after
Leonard's conversation with the inmate he found himself on the phone
with a man he believed to be a hit man. Instead, it was a federal agent.

The agent
asked Leonard if he was certain he wanted to go through with the killing
and Leonard said he was, according to the affidavit. When the agent
asked Leonard if he wanted the witness to suffer, Leonard told him no,
because "that takes too much time," the affidavit says.

The witness
told investigators that Leonard had told him about the explosion a week
before it occurred and that Leonard was already shopping for the Ferrari
that he intended to buy with the insurance money, according to a
probable cause affidavit related to the original charges.

Investigators believe Leonard and the others orchestrated the fatal
explosion by removing a gas fireplace valve and gas line regulator so
that the house filled up with natural gas, then set a microwave to start
on a timer, sparking the blast.

Curry said
in February he would seek life without parole for Shirley and the
Leonards because a jury was unlikely to choose the death penalty.